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Last updated: April 25, 2025

SCWE-033: Chain Split Risks

Stable Version v0.0.1

This content is in the version-(v0.0.1) and still under active development, so it is subject to change any time (e.g. structure, IDs, content, URLs, etc.).

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Description

Chain split risks refer to vulnerabilities that arise when a blockchain splits into multiple chains, such as during a hard fork. This can lead to: - Confusion or inconsistencies in contract logic. - Loss of funds or data. - Exploitation of vulnerabilities in cross-chain operations.

Remediation

  • Handle chain splits: Implement logic to handle potential chain splits.
  • Use chain identifiers: Include chain identifiers in cross-chain communications.
  • Test thoroughly: Conduct extensive testing to ensure contract logic is robust.

Examples

  • Vulnerable to Chain Splits 

    pragma solidity ^0.8.0;

contract ChainSplitVulnerable {
    function processTransaction(bytes memory data) public {
        // Process transaction without chain split handling
    }
}

  • Protected Against Chain Splits 

    pragma solidity ^0.8.0;

contract ChainSplitProtected {
    uint public chainId;

    constructor(uint _chainId) {
        chainId = _chainId;
    }

    function processTransaction(bytes memory data, uint transactionChainId) public {
        require(transactionChainId == chainId, "Invalid chain ID");
        // Process transaction
    }
}